Say a conscripted man was severally autistic, or had OCD which made living in a dirty trench impossible to deal with, were any allowances made for these neurodivergent people?
By the last year of the war, there were four levels of fitness for UK conscripted soldiers, from 1 (totally fit) to 4 (totally unfit). Conscripts ranked 2 or 3 might be trained up or given jobs off the battlefield in order to serve the war effort in another capacity.
A National Archives blog post delves into some of the physical and psychological issues that prevented some people from passing fit. Autism and OCD wouldn't be listed as conditions, but the symptoms might have fallen under "neurasthenia" or "nervous disability" and led to a lower classification.
(The classification would not have exempted him from censure from others. Young women often gave white feathers to conscientious objectors or others whom they deemed cowardly by staying on the home front--even to help the war effort--instead of doing the "manly" thing and taking to the battlefield.)